Figure 3.

Resonance Raman spectra of the oxy complex of Q(E7)G and the Y(B10)L mutants of Chlamydomonas oxyHb. The spectra with ¹⁶O₂ and ¹⁸O₂, as well as the difference spectra (¹⁶O₂ − ¹⁸O₂), are shown for both the mutants. The frequencies of the ν_Fe—O2 mode are assigned at 569 (544 with ¹⁸O₂) and 561 (537) cm⁻¹ for Q(E7)G and Y(B10)L, respectively. The difference feature at 431/419 cm⁻¹ in Q(E7)G may arise from the Fe—O—O bending mode (see refs. 23 and 35), which is not detected in Y(B10)L. The ν_O—O modes are not detected in these two mutants.